sustainable living in the great white North

A scientist and a technologist walk into a bar…

Do you remember how glowingly I spoke of rocket mass heaters? How excited I was to have one as the primary heating system in our home? And it wasn’t just me- Shane was equally enthusiastic about the technology, possibly even more so. The potential to build our own heating system, for relatively little money, the possibility of storing heat in mass- that would in turn provide a cozy sitting area, the efficiency of the burn, our very positive experiences with rocket stoves– all of these qualities made rocket mass heaters extremely attractive to us. Add to that the fanfare, oh the fanfare…

Well I can’t stand rocket mass heaters. I would never build another one, unless I had an immense amount of time on my hands with absolutely nothing better to do and wanted an outdoor bench as a novelty item to be used periodically in the cooler fall months. And I’ll tell you why…

They are extremely finicky. It can be exciting during the build: getting the measurements just right, reshaping the bell chamber, getting the length of run perfect for maximum efficiency. Sure, it wears on a person after a while, but there is immense satisfaction in finally getting the bloody thing just right. That rocket sound when everything is working perfectly- WOW! But don’t get too excited- just because it’s perfect, doesn’t mean that it will work all the time.

If there is a strong wind, or say very cold temperatures (hello Canadian prairie!) all bets are off. Now you’ll have to fight a down-draft, or a nice column of very heavy cold air. Good luck getting that thing started. Oh sure, you can open a window to rebalance the air pressure, install a fan in the pipe to try and combat the problem- and if you’re persistent (like Shane) you may even get it started. This time. But try again the next morning when your wife has already moved out in frustration and you’re feeling blue- and very cold.

And then there’s the fact that you must not have any other occupation. This is perhaps appealing to some- say monks, or hobbits- who might have all day to contemplate life and feed the fire. But the average person cannot sit by the feed tube all day long, feeding the endlessly hungry beast little pieces of wood lovingly chopped down to (again) just the right size. I can only imagine what was going through Shane’s head (because again- I wasn’t here) but I’m betting it wasn’t, “man am I glad to have all of this time away from all of the other tasks on my list. I hope that I can do this every day.”

And then there are the marvellous fumes. You can’t actually close the top of the stove, for very long anyway, because you need to keep feeding it (remember?) and it needs a bit of air. This is no sealed unit you’re dealing with. So if you have breathing problems to start with, or allergies, you’ll enjoy hours of feeling like someone has your lungs in an iron grip and is slowly squeezing the air out.

There are positives. The mass does actually retain the heat for a good while. And since you can’t leave the heater during your waking hours you will get to enjoy that cozy warmth under your bum, periodically, when you’re not up and feeding the thing more sticks. But that mass does relatively little to add heat to a cold room. And it is indeed efficient- there is hardly any ash left over after burning piles and piles of expertly chopped sticks. And you can shape it to look like a dinosaur, or a mermaid, if that’s your thing.

Unfortunately the negatives far outweighed the positives for me. We tore the f*cking thing out and replaced it with a Blaze King Princess (thank you Analogman, for the very helpful advice and support). Guess what? The house is perfectly comfortable now, and it’s only been in two days. Last night, in fact, I was broiling while we watched movies in our new home and had to strip off the layers of clothing I was convinced would become my new second skin. The fire was still going this morning and kept the temperature of the house comfortable enough that I don’t even require layers. Shane didn’t even need to add wood right away- he just increased the temperature and the fire burst back into life. Yes Virginia, there is a Santa Claus.

There’s been no fumes, no leaks, no fighting down-drafts, no fighting air pressure, no swearing and threatening to leave the country for warmer climes (though I could use a vacation after all of our troubles)… Imagine that. Just warmth and comfort.

And before any rocket mass heater fans (I know you’re out there- and fanatical) write me about how we should have stuck it out, or tried a few more things- save it. The reason we embarked on this experiment was because- between a technologist and scientist- we’re game to try out just about any neat sounding idea. And we understand that no experiment goes right the first time, or the second time, and sometimes not the twelfth, or the twentieth time. We’re perfectly comfortable with reworking a project dozens of times to get the predicted results. We’re very accustomed to making adjustments, and careful measurements counting. The build was perfect but this idea does not deliver. Not in our climate and not, in my opinion, as a safe and effective indoor option. And no- I wouldn’t use it in a greenhouse either (as we at one time planned on doing) because I don’t expect to want to sit in a greenhouse long enough to get the mass up to the right temperature to be helpful.

I have a lot of cleaning to do now. Taking out a huge section of the mass heater made quite the mess and there’s dust everywhere. But I can comfortably do that now- in my underwear if I so choose.🙂

*I’d be remiss if I didn’t say a special thanks to Chad at Fireplace Stove World, in Edmonton, who was immensely helpful and patient with me, even though the road conditions (and lack of heat in days, feelings of total hopelessness, etc) had me in a terrible state by the time I got there. Thank you.

Guess we’d better get the smaller model or we’ll fry! The 2nd and over generation Tasmanians all sit outside at cafes in the middle of winter in shorts and tshirt and maybe a beanie. Not quite naked, but who knows what happens at home? They just don’t feel the cold. Nobody at all has central heating and when we have visitors they all freeze. It’s usually over 10C, often 15C during the day, so I don’t know what they’re complaining about – they’ve all got soft!

I could never deal with the kind of constant attention the RMH needs- that was supposed to be Shane’s job. And he did it alright, but I think even he was surprised at the amount of tending and is none too sorry to be done with it.🙂

It must have been so hard to give up that project, in spite of the bitter cold. I am glad you found your Santa Claus, and revived the season’s Spirit. You are inspiring when you point out that success often comes after dozens of ideas that didn’t yield what was wanted.

You bring back memories of when I built a house. I carefully planned it so we had a length of drain tile run from the air intake of the wood stove, under the house, continue underground several more yards/meters, and finally out the side of the hillside. Nice, preheated, fresh air, right? Perhaps the length was too long, or the diameter wasn’t large enough to suck enough air fast enough. Yes, the end of the drain tile stayed open to the air. I covered it with screen to keep anything out that would clog it. On the south-facing, steep hillside, even snow didn’t accumulate around it. The wood stove “burped” smoke. The lid flew up and down with a BANG! each time.

And, ah, yes, thermal mass. We built on an extra thick slab on top of extra insulation. It was supposed to absorb the excess solar heat, and radiate it back to us. We had plenty of solar heat, and often opened the windows near the ceiling on the coldest days to keep the temperature below 80, but when that slab got cold, it stayed cold for a loooooong time. And the heat didn’t dissipate very well in spite of all the re rod we put in it: warm where the sun was hitting it, cold everywhere else. Too bad we didn’t build underground, as we had originally planned. Maybe the slab would have worked better over our heads where it could absorb more of the excess heat…but then the heat wouldn’t rise so nicely.

I love Shane’s feet: square-toed like mine😉 I think it is a sign of walking around bare footed and avoiding pointy-toed shoes.

It was a surprisingly difficult decision to make. I think because we’d been such enthusiasts, and had put in sooo much work. Nothing like -30 C temperatures to help a person make a decision though. And I have to admit- not that it’ll come as a surprise, given the tone of my last two articles- I was seriously losing it. I made it through anxiety, frustration, anger, sadness, all the way to hopelessness in the span of a week. Luckily just when it seems I’m down for the count, I’m ready for one more round. But it was close…🙂

This story reminds me of the house I built in 2002 in St Albert. WITHOUT forced air. We hired a very reputable company to plumb me a complete water radiant system. An entire heating system, all infloor of course, with a boiler system in the basement. Enter the aforementioned contractor that had only ever done construction in massive commercial buildings.We took possession of our dream home on Dec 22. By Dec 26th I was ready to burn the house down. Have you ever tried,begged,pleaded to have anything done between Dec 21 and Jan 15. The contractors had wired the master bedroom(west side of house) to the den thermostat on the east side of house) and the den thermostat to the master bedroom side of the house. The thermostats controll an area in the house called Zones. It took 2 weeks to figure out that when we turned the heat up in the bedroom side of the house we were actually turning it up in another section of the house and vice versa. I had windows open in one room in the dead of winter and in the other room,the bedroom we had seven blankets and an electric heater. This sounds very easy to figure out ,you would think ? This was in a small house that took about 3 days to cool down after we turned the system off completely, it wasn`t easy to figure out at all.After we spent weeks with this contractor monkeying around we finally hired a specialist. I should mention that when you move a thermostat up a few degrees with a furnace you know right now! with radiant heat it takes hours if not days to feel a significant change.
We ended up spending over $20,000 dollars having the entire system redone. Oh yes..this was before they actually had a governing body looking at these radiant systems so it was all up to code in December 2002. By March 2003 it wasn`t up to code.Go figure. Can you hear me when the new contractor says to me..This system is no longer up to code..except for a garage. Then there was the contractor who used screws(not glue)on the very expensive engineered floor. we got a leak from the water line in May 2003.

Yikes! That does sound like quite the headache. I agree with publicizing mistakes as we go. I think it’s a weakness of a lot of the ‘movements’ out there. If you really want to encourage others to (do this or that/ fill-in-the-blank), don’t mislead them.

And it is pretty comfy in here! I still can’t quite get over the fact that I’m walking around barefoot.🙂

Thank you! All I read was hype… lots of it regarding the rocket mass heater. Now I know when I build my shop/greenhouse to look into other alternatives. I live in Southern Alberta so know what you mean with last weeks blizzard – must have been a nightmare living through that with no dependable heat!!

Ya, we kind of got swept away by that too- took a workshop, bought a book, loads of time on forums, hours and hours of building and testing. In fact we’re probably responsible for some of the hype, as my earlier articles may attest to. Alas, nothing beats experience, and experience over time. Hopefully some can avoid our mistakes as I post them.🙂

I’ve never been a huge fan of the rocket mass heater concept. Sure, a rocket stove is easy to build, but when it comes to mass-heating, I prefer a masonry heater. I used one in a home of my in-laws years ago during December-January while we lived with them for those two months.

An enclosed firebox with tempered glass door; combustion air drawn through a duct from the outside (IIRC, the intake also had an electric blower to help get things started, but didn’t need to run long before there was sufficient draw to be self-sustaining), with a heat-exchanger to pre-warm that air. Even in the coldest Wisconsin Winter nights, we burned just two charges of kindling-sized wood inside paper shopping bags (one bag full of kindling = 1 charge). One charge around 5 PM and another around 9 PM. The burn is extremely hot and efficient. Nearly 100% of the heat released is trapped in the masonry. It remained warm the entire night. Another charge in the morning would be sufficient for the next morning’s heat.

One could build such a heater out of cob. The only manufactured components to buy would be the firebox material: the door and firebrick or heat-resistant cement like FIREROK by Ceratech (a “green concrete” with high fly-ash content).

We did consider a masonry heater initially (and some of the Russian versions we looked at were gorgeous!) but got caught up in the rocket mass heater craze. (I still stand by the virtues of a rocket stove, just not the heaters.) The whole “super cheap, super easy to build, fuel-efficient” thing was really appealing. In retrospect I don’t think that building a masonry heater would’ve been a whole lot more work- considering the amount of fiddling and adjustment required to build a good mass heater, that ultimately only worked sometimes…

I’m a little gun-shy about getting into building any more heaters but we’ll see where we’re at down the road, and that’ll depend in large part whether we expand the house. Our current system is working beautifully.🙂

Good for you for knowing when to cut your losses…and thank you for the frank assessment of the RMH for a zone 2 climate. We were considering installing one when we eventually build…now we’re back to the drawing board, but I’d rather learn from your mistakes where I can😉